OP--you might look into marketing your pet services towards visitors too. Out on the islands, many visitors want to bring their pets. Many accommodations (vacation rentals and the like) are NOT pet friendly.
Perhaps you could fill the void--visitors bring their dogs to the island for the day for a beach day but at night the dogs stay at your "hotel"
I know out on Kiawah and Seabrook Islands there are huge number of animal lovers. Seabrook has its own property owners' group--SIDOGS (Seabrook Island dogs). I'm sure these property owners do travel and need to board their pets from time to time.